The install process is pretty much the same than it has been since Windows 7. I created a virtual 20 GiB drive (which later turned out to be not enough) and chose to install on the non-initialized drive. No surprises there. This is what runs as out-of-box-experience:

It looks very much like Windows 8.1. Notice how the window border is quite thin. This is something Microsoft hasn't done in their operating systems ever before. Internet Explorer is still version 11 as in Windows 8.1 and the reported user-agent string is: Mozilla/5.0 (Windows NT 6.4; WOW64; Trident/7.0; rv:11.0) like Gecko.

It sees the virtual CPU incorrectly as a Xeon, however the physical CPU is of Sandy Bridge microarchitecture:

Finally the start menu is something, that I would like to use. Microsoft had a decent start menu on Windows 7, they dropped it for Windows 8 and restored a crappy version for Windows 8.1. This time it works and the stupid full-screen-apps -mode is gone. The start menu will contain both the classic and tile-based apps at the same time:

This is what computer properties and disc management look like. Pretty much the same than in Windows 7:

Also control panel is unchanged:

The version is displayed as Windows NT 6.4, but apparently it is going to change and the version number will be 10. Also IPv6 works as expected:

One other thing I also changed, was to speed up the preview image process. As a default, new installations are on a slow track, but I wanted to get the new versions a bit faster. This is a bit funny thing, the only way to change it is to go for a new-style full-screen settings (luckily this runs in a window). There doesn't seem to be a control panel -setting for this. For details see: How to Stay Up to Date and Get the Latest Windows 10 Technical Preview Builds. This is how I changed the setting:

To upgrade into a newer build (9860 in this case) it goes something like this. I found the process quite amusing:

When the slow process completes, the bottom right corner will state the new version:

During the testing I haven't had many issues, but here is one:

For some reason system interrupts started hogging lot of CPU-resources. That is something I've never seen on any Windows. After a nice reboot, the problem disappeared. That's what you get from running beta operating system.

Also, my original 20 GiB of disc space ran out after couple of new build upgrades. This is what happened:

There wasn't much else to do, except to shut down the Windows 10 instance. Go to virtualization host (Linux) and add 10 GiB of space into the virtual drive:qemu-img resize Windows\ 10.qcow2 +10G

As no Windows version is capable of actually expanding the partition and file system on a grown drive, I mounted an ISO-image of GParted and booted the virtual machine from that. It could expand the system partition in a couple of seconds (it is a really good partition manager software). After having 30 GiB of space, the latest build upgraded without problems.

My thanks goes to F-Secure. I've been running their new FS Protection (still on beta) on my Windows 10 and it works really well.